kalarm/undo.h

   1 /*
   2  *  undo.h  -  undo/redo facility
   3  *  Program:  kalarm
   4  *  Copyright © 2005-2011 by David Jarvie <djarvie@kde.org>
   5  *
   6  *  This program is free software; you can redistribute it and/or modify
   7  *  it under the terms of the GNU General Public License as published by
   8  *  the Free Software Foundation; either version 2 of the License, or
   9  *  (at your option) any later version.
  10  *
  11  *  This program is distributed in the hope that it will be useful,
  12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  14  *  GNU General Public License for more details.
  15  *
  16  *  You should have received a copy of the GNU General Public License along
  17  *  with this program; if not, write to the Free Software Foundation, Inc.,
  18  *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  19  */
  20
  21 #ifndef UNDO_H
  22 #define UNDO_H
  23
  24 /**  @file undo.h - undo/redo facility */
  25
  26 #include "autodeletelist.h"
  27
  28 #include <kalarmcal/kaevent.h>
  29
  30 #include <AkonadiCore/collection.h>
  31 #include <QList>
  32 #include <QStringList>
  33
  34 class UndoItem;
  35 using namespace KAlarmCal;
  36
  37
  38 class Undo : public QObject
  39 {
  40         Q_OBJECT
  41     public:
  42         enum Type { NONE, UNDO, REDO };
  43         // N.B. The Event structure must be constructed before the action for
  44         // which the undo is being created is carried out, since the
  45         // don't-show-errors status is not contained within the KAEvent itself.
  46         struct Event
  47         {
  48             Event() {}
  49             Event(const KAEvent&, const Akonadi::Collection&);
  50             KAEvent        event;
  51             mutable Akonadi::Collection collection;
  52             QStringList    dontShowErrors;
  53         };
  54         class EventList : public QList<Event>
  55         {
  56         public:
  57             void append(const KAEvent& e, const Akonadi::Collection& c)  { QList<Event>::append(Event(e, c)); }
  58         };
  59
  60         static Undo*       instance();
  61         static void        saveAdd(const KAEvent&, const Akonadi::Collection&, const QString& name = QString());
  62         static void        saveAdds(const EventList&, const QString& name = QString());
  63         static void        saveEdit(const Event& oldEvent, const KAEvent& newEvent);
  64         static void        saveDelete(const Event&, const QString& name = QString());
  65         static void        saveDeletes(const EventList&, const QString& name = QString());
  66         static void        saveReactivate(const KAEvent&, const Akonadi::Collection&, const QString& name = QString());
  67         static void        saveReactivates(const EventList&, const QString& name = QString());
  68         static bool        undo(QWidget* parent, const QString& action)
  69                                               { return undo(0, UNDO, parent, action); }
  70         static bool        undo(int id, QWidget* parent, const QString& action)
  71                                               { return undo(findItem(id, UNDO), UNDO, parent, action); }
  72         static bool        redo(QWidget* parent, const QString& action)
  73                                               { return undo(0, REDO, parent, action); }
  74         static bool        redo(int id, QWidget* parent, const QString& action)
  75                                               { return undo(findItem(id, REDO), REDO, parent, action); }
  76         static void        clear();
  77         static bool        haveUndo()         { return !mUndoList.isEmpty(); }
  78         static bool        haveRedo()         { return !mRedoList.isEmpty(); }
  79         static QString     actionText(Type);
  80         static QString     actionText(Type, int id);
  81         static QString     description(Type, int id);
  82         static QList<int>  ids(Type);
  83         static void        emitChanged();
  84
  85         // Types for use by UndoItem class and its descendants
  86         typedef AutoDeleteList<UndoItem> List;
  87
  88     Q_SIGNALS:
  89         void               changed(const QString& undo, const QString& redo);
  90
  91     protected:
  92         // Methods for use by UndoItem class
  93         static void        add(UndoItem*, bool undo);
  94         static void        remove(UndoItem*, bool undo);
  95         static void        replace(UndoItem* old, UndoItem* New);
  96
  97     private:
  98         Undo(QObject* parent)  : QObject(parent) { }
  99         static void        removeRedos(const QString& eventID);
 100         static bool        undo(int index, Type, QWidget* parent, const QString& action);
 101         static UndoItem*   getItem(int id, Type);
 102         static int         findItem(int id, Type);
 103         void               emitChanged(const QString& undo, const QString& redo)
 104                                            { Q_EMIT changed(undo, redo); }
 105
 106         static Undo*       mInstance;     // the one and only Undo instance
 107         static List        mUndoList;     // edit history for undo, latest undo first
 108         static List        mRedoList;     // edit history for redo, latest redo first
 109
 110     friend class UndoItem;
 111 };
 112
 113 #endif // UNDO_H
 114
 115 // vim: et sw=4: